Afro No-Clash : composing syncretic African/Western music : eleven compositions and the frameworks for their systematic analysis

This PhD consists of an artistic work (an album of music) and an exegesis. The album contains eleven works for a variety of ensembles, including an eight-piece pop fusion group, a string quartet, an eleven-piece a cappella ensemble, a five-piece contemporary classical ensemble and a six-piece percussion ensemble. Each of these works embraces a blend of African and Western techniques and aesthetics. These works are the result of a compositional praxis which is closely integrated with a theoretical framework that I develop in the exegesis. The purpose of the exegesis is to provide a framework from which to understand the compositions. Perspectives such as postcolonialism are immediately engaged because of the fact that two distinct world cultures are referenced by these compositions. Similarly, the musical aesthetics of the two source cultures are examined because I need to understand the ways that the value systems are expressed in musical terms, and how they might interact in cross-cultural composition. Examination of the literature reveals that there has been a trend in recent decades towards cultural analysis of cross-cultural music but very little work has been done on the technical analysis of such works (Utz 2003). A preliminary list of issues is developed from a survey of ten relevant composers’ works and these issues are categorised into three analytic dimensions: the contextual (cultural), aesthetic and technical. African “musics” and musical cultures are discussed with regard to issues of Western interpretation (Agawu 2003) and appropriate representation, social and cultural preferences and aesthetic values. Likewise Western musical culture is examined in order to understand its colonial impact, its stylistic consistency and ideas that have emerged about aesthetic preferences and the interpretation of meaning (Cone 1972; Kivy 2001). Four frameworks are developed to address each of these analytical dimensions. The first deals with cultural identity and the appropriation of musical ideas, the second with the sensitivity of certain materials. The third framework enables the examination of the aesthetic preferences for each of the cultures involved and the fourth framework provides a taxonomy and vocabulary of terms for use in analysis of the structural and other technical features of cross-cultural Western/African musics. These four frameworks are applied to the eleven compositions that I have completed for this project. I identify distinct approaches to appropriation, aesthetic preferences, the predominance of rhythmic structure and the performative embodiment and narrative transformational processes in my compositions. I conclude by categorising the technical and stylistic preferences embodied in my work, and identifying possible future directions for my compositions and the development of the analytical frameworks

Normalization by Evaluation in the Delay Monad: A Case Study for Coinduction via Copatterns and Sized Types

In this paper, we present an Agda formalization of a normalizer for simply-typed lambda terms. The normalizer consists of two coinductively defined functions in the delay monad: One is a standard evaluator of lambda terms to closures, the other a type-directed reifier from values to eta-long beta-normal forms. Their composition, normalization-by-evaluation, is shown to be a total function a posteriori, using a standard logical-relations argument. The successful formalization serves as a proof-of-concept for coinductive programming and reasoning using sized types and copatterns, a new and presently experimental feature of Agda.Comment: In Proceedings MSFP 2014, arXiv:1406.153

Policy Coordination in an International Payment System

Given the increasing interdependence of both financial systems and attendant payment and settlement systems a vital question is what form should optimal policy take when there are two connected payment systems with separate regulators. In this paper I show that two central banks operating in a non-cooperative way will not have an incentive to achieve the optimal allocation of goods. I further show that this non-cooperative outcome will be supported by a zero intraday interest rate and constant fixed exchange rate. This is in contrast to recent research; which has shown that domestically a zero intraday interest rate will achieve a social optimum and that the central bank has an incentive to achieve it.Payment, clearing, and settlement systems; Exchange rate regimes

Estimating the Structure of the Payment Network in the LVTS: An Application of Estimating Communities in Network Data

In the Canadian large value payment system an important goal is to understand how liquidity is transferred through the system and hence how efficient the system is in settling payments. Understanding the structure of the underlying network of relationships between participants in the payment system is a crucial step in achieving the goal. The set of nodes in any given network can be partitioned into a number of groups (or "communities"). Usually, the partition is not directly observable and must be inferred from the observed data of interaction flows between all nodes. In this paper we use the statistical model of Copic, Jackson, and Kirman (2007) to estimate the most likely partition in the network of business relationships in the LVTS. Specifically, we estimate from the LVTS transactions data different "communities" formed by the direct participants in the system. Using various measures of transaction intensity, we uncover communities of participants that are based on both transaction amount and their physical locations. More importantly these communities were not easily discernible in previous studies of LVTS data since previous studies did not take into account the network (or transitive) aspects of the data.Payment, clearing, and settlement systems; Financial stability

When is a container a comonad?

Abbott, Altenkirch, Ghani and others have taught us that many parameterized datatypes (set functors) can be usefully analyzed via container representations in terms of a set of shapes and a set of positions in each shape. This paper builds on the observation that datatypes often carry additional structure that containers alone do not account for. We introduce directed containers to capture the common situation where every position in a data-structure determines another data-structure, informally, the sub-data-structure rooted by that position. Some natural examples are non-empty lists and node-labelled trees, and data-structures with a designated position (zippers). While containers denote set functors via a fully-faithful functor, directed containers interpret fully-faithfully into comonads. But more is true: every comonad whose underlying functor is a container is represented by a directed container. In fact, directed containers are the same as containers that are comonads. We also describe some constructions of directed containers. We have formalized our development in the dependently typed programming language Agda

Rediscounting Under Aggregate Risk with Moral Hazard

Freeman (1999) proposes a model in which discount window lending and open market operations have different effects. This is important because in most of the literature, these policies are indistinguishable. However, Freeman's argument that the central bank should absorb losses associated with default to provide risk-sharing stands in stark contrast to the concern that central banks should limit their exposure to credit risk. We extend Freeman's model by introducing moral hazard. With moral hazard, the central bank should avoid absorbing losses and Freeman's argument breaks down. However, we show that policies resembling discount window lending and open market operations can still be distinguished in this new framework. The optimal policy is for the central bank to make a restricted number of creditors compete for funds. By restricting the number of agents, the central bank can limit the moral hazard problem. By making them compete with each other, the central bank can exploit market information that reveals the state of the economy.Payment, clearing, and settlement systems; Financial markets; Central bank research

Liquidity Provision and Collateral Haircuts in Payments Systems

Central banks play a pivotal role in well-functioning payments systems by providing liquidity via collateralized lending. This article discusses the role of collateral and haircut policy in central bank lending, as well as the distinguishing features of the central bank’s policy relative to private sector practices. It presents a model that explicitly incorporates the unique role of central banks in the payments system and argues that central banks must consider how their haircut policies affect the relative price and liquidity of assets, the market’s asset allocation, and the likelihood of participants to default. Furthermore, under extraordinary circumstances, there is a rationale for the central bank to temporarily reduce haircuts or broaden the list of eligible collateral to mitigate the shortage of liquidity in the market.

A Model of Tiered Settlement Networks

This paper develops a model of settlement system to study the endogenous structure of settlement networks, and the welfare consequences of clearing agent failure. The equilibrium degree of tiering is endogenously determined by the cost structure and the information structure. The degree of tiering is decreasing in the fixed cost of operating the second-tier network and the availability of public credit history. Furthermore, the welfare effects of clearing agent failure can be decomposed into operational inefficiency and the loss of private information.Payment, clearing, and settlement systems

Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies

Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity “set” during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC